Pump filters

ABSTRACT

A pump filter comprises a housing having two independent chambers in communication with each other. The chambers are vertically spaced with the upper chamber being further defined by a mounting plate and the lower chamber communicating with a suction tube. A filter screen is positioned in the upper chamber and the lower chamber includes a swing valve which opens and closes the mouth of the suction tube. A removable plug communicates with the second chamber to permit access thereto.

United States Patent 1191 Woods et al.

[111 3,811,571 1451 May 21, 1974 PUMP FILTERS [75] Inventors: James F. Woods, Craigsville; Gary Paul Kerns, Fenwick, both of W. Va.

[73] Assignee: Standard Hydraulics Service, Inc.,

Craigsville, W. Va.

[22] Filed: July 3, 1972 [2]] Appl. No.: 268,684

[52] (1.8. Cl. 210/136, 210/416 [51] Int. Cl Bld 35/02 [58] Field ofSearch ..2lO/l36,4l6,3ll,445,

63,l89 3/1867 West Zl0/l3h 719,913 2/l903 Wackcruw 2l0/l36 Primary ExaminerFrank A. Spear, Jr. Attorney, Agent, or Firm-Webb, Burden, Robinson & Webb and the lower chamber communicating with a suction tube. A filter screen is positioned in the upper chambet and the lower chamber includes a swing valve 5 1 References Cited which opens and closes the mouth of the suction tube. UNITED STATES PATENTS A removable plug communicates with the second chamber to permit access thereto. 167.550 9/[875 Magulre 210/136 3.037.636 6/1962 Mafurlin 210/429 5 Claims, 5 Drawing Figures 2 I2 1 1 i 4V 1 x A 7 l3 I4 l7- 26 27 F 1 111 r 111 Morgan 210/ PUMP FILTERS This invention relates to pump filters and, more particularly, to pump filters positioned between a pump and a oil reservoir of the type found on heavy industrial equipment such as miners.

Large pieces of industrial equipment such as miners normally have a single pump and an oil reservoir to supply the various hydraulic components of the equipment. These oil reservoirs are continually being contaminated by the environment surrounding the equipment. For example, on miners, the reservoir becomes contaminated with coal dust and bits of coal which often reach peanut size. The various type covers used on the reservoirs are continually lost and often the screens which cover the openings to the reservoir are purposely removed to facilitate adding oil. These contaminants then get sucked into the intake side of the pump, thereby blocking the suction as well as decreasing the life of the pump and the other hydraulic components supplied thereby. Normally filters are not used on the suction side of the pump because of the space limitations, and also because of the problem with affecting pump suction. And, of course, filters on the return side of the hydraulic systems have no affect on contaminants entering the reservoir as previously described. As a practical matter, large pieces of equipment are routinely shut down for purposes of cleaning the pump systems and down time on a large piece of equipment is very costly.

Our pump filter solves the aforementioned problems by providing a filter which can be used on the suction side of the pump and which can be routinely cleaned by the simple removal of a plug. This then avoids down time delays and increases the life of the pump and the other hydraulic components by keeping the contaminants thereout of in the first instance.

Our invention is a pump filter which connects on the suction side of a pump and which extends into an oil reservoir. The pump filter housing contains two chambers in vertical alignment and cooperation with each other. The upper chamber includes a screen filter, and the lower chamber contains a swing valve which opens and closes the mouth of the suction tube communicating between the oil reservoir and the second chamber. A plug access means permits easy entry into the second chamber to clean the screen and remove the contaminants which fall off the screen and collect on the swing valve in the second chamber when the pump is not operating.

In the accompanying drawings, we have shown one preferred embodiment of our invention in which:

FIG. 1 is a section through the pump filter with the valve in the closed position;

FIG. 2 is a side elevation of the filter pump; FIG. 3 is a section taken along lines lIIIII of FIG. 1;

FIG. 4 is a section through the pump filter in which the valve is in the open position; and

FIG. 5 is a section through the pump filter with the valve in the closed position and the access plug removed.

The pump filter, generally designated 10, is mounted and is operable in the vertical position. The pump filter includes a main housing 11 having several components, a mounting plate 12 secured to the upper part of housing 11 and a suction tube 18 secured to the lower part of housing 11, FIGS. 1 and 2.

Specifically, housing 11 includes an annular first member 13 welded to the mounting plate 12. Mounting plate 12 and annular member 13 define an internal chamber 14 which is frusto dome shaped and which includes a top opening 29 exiting therefrom.

Annular member 13 threadably engages a shoulder member 15 which extends inwardly of chamber 14 and provides a seat for a filter screen to be described hereinafter. Shoulder member 15 defines a central passageway 16 communicating with chamber 14.

A cylindrical second member 17 is welded to the bottom of shoulder 15 and is maintained in sealable engagement with annular first member 13 by means of t standard O-rings 35. Member 17 defines internal chamber 20 which communicates with passageway 16. Chamber 20 is arch shaped in cross section, FIG. 3, but it can also be circular in cross section as is chamber 14. An elongated suction tube 18 is welded to the bottom of second member 17 and communicates with chamber 20 at mouth 19 of suction tube 18.

A swing valve 21 is welded intermittently along and to rod 22 which is pivotally mounted in openings 31 in the side walls which define chamber 20. Stop plates 34 maintain rod 22 in place. Swing valve 21 and rod 22 may also be pivotally mounted in other ways, as for example, by means of end supports positioned on the .upper surface of suction tube 18 and which contain bearing type openings to accommodate the rod ends. Swing valve 21 rests on the top of suction tube 18 which forms the valve seat 32 therefor, but is positioned sufficiently spaced from the top of suction tube 18 at the pivotal connection to permit free pivoting thereof. Swing valve 21 is arch shaped in cross section to conform with chamber 20, but such a configuration can also be employed with a cylindrical chamber. A stop block 33 is welded to the interior of second member 17 so as to extend into chamber 20 and limit the upward movement of swing valve 21. v

A square plate 23 is machined to conform and is welded to cylindrical second member 17 to provide a flat surface along the outer surface thereof. A clearance opening 25 extends through the wall of member 17 and cooperates with a threaded opening 36 of smaller cross section in plate 23. A plug 24 threadably engages with the opening 36 so as to shut off opening 36 with O-ring No. 37 but to permit access to chamber 20 by the removal thereof. Plug 24 terminates in a large hex nut and an extended knurled portion 26 welded thereto which is inset in the form of a standard socket 27, FIG. 2. Plug 24 can, therefore, be removed either by an end wrench on the hex nut or an Allen wrench used within the inset socket 27.

A filter screen having either a flat, dome or frusto shape in conformity with chamber l4v is positioned in chamber 14 so as to rest on shoulder member 15. The flat portion of screen 28 extends across the top opening 29 of the mounting plate 12. The mounting plate 12 includes four bolt holes 30 which align with a standard pump (not shown).

The operation of our pump filter is as follows. The pump filter is vertically attached to the pump by means of bolts extending through bolt holes 30 in standard fashion. The pump filter 10 extends vertically downward from the pump so that the suction tube 18 is immersed in the oil reservoir (not shown). When the pump is operating, the suction lifts the swing valve 21 into an upright position against stop 33. The oil flows up suction tube 18, out through mouth 19, into chamber 20, through passageway 16, into chamber 14 through the screen 28 and out of top opening 29 into the pump. The contaminants collect on screen 28.

When the pump is turned off, the swing valve 21, by gravity, closes off mouth 19 as it seats itself on valve seat 32. The larger contaminants which have been held against the screen 28, fall onto the top surface of swing valve 21. The contaminants can be cleaned out of chamber 20 by merely removing the plug 24 which provides access to chamber 20. In addition, the screen can be cleaned off by insertion of a small instrument into chamber 26 and up through passageway 16 into chamber 14. The screen can also be easily replaced by turnably disengaging annular chamber 13 from shoulder member 15. The mouth 19 of suction tube 18 is sufficiently large in cross section so that if the swing valve 21 cannot open completely because of contaminants resting thereon from previous use, the pump can still get sufficient oil. Normally, at startup, a coarse mesh screen is employed to maximize the pump suction and remove coarser contaminants and this screen can then be replaced with a finer mesh screen.

Several of these pump filters have been in extended service and by cleaning the pump filter after every eight hour shift, no extended down time at all is required on the equipment. In addition, this has increased the life of the pump, as well as the hydraulic circuits and components operative therefrom.

We claim:

1. A pump filter for use on mine equipment hydraulicsystems and the like comprising a vertically extending housing terminating at an upper end in a mounting plate adapted for securement to a pump, said housing including a first chamber exiting through the mounting plate to communicate with the pump and a second chamber positioned below the first chamber and communicating therewith, an elongated suction tube depending from the housing and having a mouth in communication with the second chamber, a swing valve pivotally connected at a lower portion of the second chamber and adapted to swing from a valve seat formed by the suction tube to open and close said mouth, filter means positioned within the first chamber and removable plug means communicating with the second chamber substantially adjacent the valve seat to permit access thereto.

2. The pump filter of claim 1 wherein an annular shoulder separates the first and second chambers, said annular shoulder defining a passageway between said chambers.

3. The pump filter of claim 1 wherein the first chamber is frusto dome or flat shaped.

4. The pump filter of claim 1 wherein the filter means includes a screen positioned on said shoulder and extending upward in the first chamber in substantial conformity therewith.

5. The pump filter of claim 1 wherein a stop block is mounted within the second chamber to an internal surface thereof to limit the upward movement of the swing valve. 

1. A pump filter for use on mine equipment hydraulic systems and the like comprising a vertically extending housing terminating at an upper end in a mounting plate adapted for securement to a pump, said housing including a first chamber exiting through the mounting plate to communicate with the pump and a second chamber positioned below the first chamber and communicating therewith, an elongated suction tube depending from the housing and having a mouth in communication with the second chamber, a swing valve pivotally connected at a lower portion of the second chamber and adapted to swing from a valve seat formed by the suction tube to open and close said mouth, filter means positioned within the first chamber and removable plug means communicating with the second chamber substantially adjacent the valve seat to permit access thereto.
 2. The pump filter of claim 1 wherein an annular shoulder separates the first and second chambers, said annular shoulder defining a passageway between said chambers.
 3. The pump filter of claim 1 wherein the first chamber is frusto dome or flat shaped.
 4. The pump filter of claim 1 wherein the filter means includes a screen positioned on said shoulder and extending upward in the first chamber in substantial conformity therewith.
 5. The pump filter of claim 1 wherein a stop block is mounted within the second chamber to an internal surface thereof to limit the upward movement of the swing valve. 